KR102155862B1 - How to make a shoe sole - Google Patents

Abstract

The present invention relates to a method of manufacturing a shoe sole (1). In order to be able to manufacture shoe soles in an economical manner and with easily selectable spring and damping properties, the present invention provides a) a plastic hose (2) extruded into a blow mold (3). Supplying a hose (2); b) blow molding the plastic hose (2) into a sole hollow body (4), wherein during the blow molding process, on the mutually opposite walls (5, 6) of the sole hollow body (4) Recesses (7, 8) are introduced in, so that some parts of the walls (5, 6) come into contact with each other to form a support structure (9) between the mutually opposed walls (5, 6). To, the blow molding step; c) removing the blow molded sole hollow body (4) from the blow mold (3); d) at least partially filling the blow-molded sole hollow body 4 with plastic bodies 10, wherein the plastic bodies 10 have a first opening 11 of the sole hollow body 4 And the filling step, which is added through.

Description

How to make a shoe sole

The present invention relates to a shoe sole manufacturing method for manufacturing a shoe sole, particularly a sole for a sports shoe.

In particular, the production of shoe soles for sports shoes is a well-known technique. This aims to have not only an economical manufacturing process, but also the possibility of having a beneficial effect on the sole of the shoe and thus the spring and damping behavior of the shoe. Here, the material used also has a significant influence.

US 2009/0013558 A1 describes a shoe in which the sole of the shoe is composed of different plastic materials, which are connected to each other, in which different polymeric materials are used. WO 2007/082838 A1 describes that E-TPU (expanded thermoplastic polyurethane) can be advantageously used for a shoe sole. These documents provide detailed information regarding these plastic materials, and therefore this document is explicitly referenced.

In addition, DE 10 2011 108 744 B4 describes shoes using E-TPU as a material for the sole. Here, single foamed plastic spheres made of this material, most of which are several millimeters in dimension, are formed in the sole, depending on the possible implementation by supplying a binder to each tool, so that the plastic spheres are connected to each other to form the body of the sole. According to another process, water vapor is supplied to the tool under the specified pressure into which the plastic spheres are inserted. Accordingly, partial melting of the plastic material occurs so that the plastic spheres are connected to each other by positive substance jointing to form the body of the sole.

The characteristics of the shoe that can be obtained from this, especially the spring and damping behavior, are not always completely satisfactory. In addition, the above-described sole production process is sometimes labor intensive and expensive.

Accordingly, it is an object of the present invention to provide a method in which a shoe sole can be manufactured in a cost effective manner and the spring and damping behavior can be adjusted in a desired manner. Therefore, the shoe sole must be economically manufacturable and must have spring and damping properties that are easy to adjust.

The solution for this object according to the present invention is the method,

a) extruding a plastic hose to supply the plastic hose into a blow mold or injection molding a plastic blank to supply the plastic blank into the blow mold;

b) blow molding a plastic hose or plastic blank into the sole hollow body, wherein recesses are introduced on the mutually opposite walls of the sole hollow body during the blow molding process so that some of the walls come into contact with each other. The blow molding step of forming a support structure between the mutually opposed walls;

c) removing the blow molded outsole hollow body from the blow mold;

d) filling the hollow part or the entire hollow of the blow-molded sole hollow body with plastic bodies, wherein the plastic bodies are added and filled through the first opening of the hollow sole body.

As the plastic bodies, in particular, spheres, ellipsoids or cylindrical bodies are used. The dimensions of the single plastic bodies in the three spatial directions are preferably 1 mm to 13 mm, particularly preferably 3 mm to 6 mm. The plastic bodies are in particular composed of a foamed plastic material.

As the material for the plastic bodies, E-TPU (expanded thermoplastic polyurethane), E-TPE (expanded thermoplastic elastomere), in particular E-TPO (expanded thermoplastic elastomere based on olefin), and/or EPP (expanded polypropylene) are preferably used. Used.

However, the sole hollow body is composed of thermoplastic polyurethane (TPU), thermoplastic elastomere (TPE), polyamide (PA) and/or rubber materials.

A preferred embodiment of the method proposes that the sealing, in particular welding, of the first opening takes place after step d) above.

It may also be provided that during or after step d) above, air is discharged from the sole hollow body. This is preferably done through a second opening arranged at a distance from the first opening.

Thus, the plastic bodies are preferably arranged in the sole hollow body without being connected to each other. Thus, single spheres or ellipsoids are loosely disposed within the sole hollow body without being connected to each other by any method.

Thus, preferably the plastic bodies are arranged in a full package, preferably under pressure, in the sole hollow body.

The manufacture of the support structure preferably creates a recess of one of the recesses, with a closed end region in one of the walls by means of a first deformation tool, and also 2 It is achieved by creating a recess on the other side with an open end region in the wall on the other side by means of a deformation tool, and the closed end area of one of the recesses is the recess on the other side. It is designed to fit within its open end. In this way, very advantageously, in such a piston-cylinder-system each spring and damping element is realized. Depending on the intended use of the shoe with the shoe sole described above, relative movement between the two recesses in the vertical direction may occur (when the shoe sole is standing on the ground). The spring rate of the sole in the vertical direction and its damping behavior are influenced by the choice of the geometry of the two recesses, in particular the closed end region on one hand and the opening of the other recess on the other. Can receive.

One embodiment of the method provides for closing the blow mold and placing an insert in the blow mold prior to performing step b), so that the insert is connected with the sole hollow body during the blow molding process.

The insert can be prefabricated by an injection molding process. The insert has a U-shaped design according to a preferred embodiment. This insert is arranged in particular as a heel clip in the area behind the sole of the shoe. The insert is preferably composed of a thermoplastic polyurethane (TPU).

It is also possible to create the interior of the sole hollow body with several hollows separated from the others by the blow molding process and then fill this interior with individual plastic bodies, but this is undesirable due to higher production requirements. In such cases they may have different physical properties that selectively affect the spring and damping properties of the shoe sole.

The plastic bodies preferably have a hardness of 75 to 90 Shore A, preferably 80 to 85 Shore A. The plastic bodies preferably have a bulk density of 100 to 300 kg/m ³ .

Regarding the expanded thermoplastic polyurethane (E-TPU) for plastic bodies inserted into the blow-molded sole hollow body, which is preferably used, refer to the following: This material is known per se, e.g. shoes Is used in For example, it is available under the name "PearlFoam" by Huntsman International LLC or "Infinergy" by BASF SE. With respect to this material, reference is expressly made to WO 2005/066250 A1, in which details of this material, namely E-TPU (expanded thermoplastic polyurethane) and a method of manufacturing the same, can be identified.

Further, with regard to the known thermoplastic elastomers of the urethane-based, reference is expressly made to WO 2010/010010 A1, in which a blend of expanded thermoplastic polymers containing a blowing agent comprising a thermoplastic polyurethane and a styrene polymer is disclosed. Thus, the polymer blend may contain at least one additional thermoplastic polymer. In particular, polyamide (PA), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene (PE), poly-propylene (PP), polyvinylchloride (PVC), cellulose and poly-oxymethylene (POM) can be used as additional thermoplastic polymers, respectively. have.

Thus, according to the present invention, in the blow molded sole hollow body, in particular, the expandable plastic foam spheres or ellipsoids are the sole base body (the sole base body is a "cage" which is pre-made for spheres and ellipsoids, respectively. It is especially utilized by the use of E-TPU, E-TPE or EPP (for example, to manufacture very light soles), which are filled in the hollow space created in the (may also be referred to as).

The support structure described above allows the sole to support the foot in an optimal manner under the load in its intended use. This is indispensable in that the plastic bodies disposed inside the hollow outsole body may provide insufficient support for the feet because the plastic bodies are otherwise loosely arranged without being connected to each other.

Since the respective spheres, ellipsoids, and cylinders preferably made of E-TPU substantially affect the damping of the shoe, the sole portion filled with the hollow space is preferably used as a midsole.

The sole may be connected to the top of the shoe (bootleg) by known sewing or bonding.

In the above, the manufacture of the sole as a complete form part has been described. Of course, the present invention can also be used where only one portion of the sole is manufactured as described, and it can be connected to another sole portion.

Extrusion of the plastic hose and immediate feeding into the blow mold in its warm state are preferred, but alternatively-as described above-injection molding of the plastic blank, in which it is later fed into the blow mold, may be provided. In this case, the injection molding process for plastic blanks is usually carried out first; If this plastic blank is transferred to a blow molding machine and has to be blow molded on it, it can be transformed into a hollow outsole body by heating it again before that.

In the drawings, an embodiment of the present invention is shown.
1 schematically shows a first process step of manufacturing a shoe sole according to the present invention.
FIG. 2 is a plan view of a shoe sole after performing the process step according to FIG. 1, wherein the hollow sole of the shoe sole is not yet filled.
3 schematically shows a subsequent process step in which the sole hollow body of the shoe sole is filled with plastic bodies.
4 shows a section AB according to FIG. 2.

1 schematically shows the beginning of the shoe sole manufacturing process. An extruder 18 plasticizes the plastic material and outputs it through an extrusion head 17, thereby producing a plastic hose 2 with the entire circumference closed. If its length is sufficiently long, it is placed in a blow mold (3) consisting of two mold halves which are enclosed in a known manner around the blow molding plastic hose (2) after moving relative to the other in the direction of the double arrow. do.

As already mentioned, alternatively, injection molding of plastic blanks which are later deformed in the blank mold 3 may be considered.

By this blow molding process, the sole hollow body 4 (see Figs. 2 and 3) that provides an accommodation space therein is produced.

A first deformation tool 13 and a second deformation tool 15 are schematically shown. When the mold halves of the blow mold 3 are closed, these tools 13, 15 are moved relative to the other tool in the direction of the arrow. By means of the tools 13, 15, support structures 9 (see FIGS. 2 to 4) are formed in the sole hollow body 4.

Although only a pair of tools 13, 15 is shown in Fig. 1, a plurality of tools 13, 15 are provided.

As can be seen from FIG. 2, a plurality of the above-described support structures 9 are currently being produced, and will be described in detail below. Since they have the purpose of providing a support function at the desired position through the contact area of the foot on the surface of the shoe sole 1, the shoe sole 1 is not adjusted laterally in a way that the shoe wearer's weight is applied. Does not bend.

Details of the support structure are apparent from FIG. 4. Here, the sole hollow body 4 includes an upper wall 5 and a lower wall 6, and these walls are disposed to face each other at a certain distance after performing the blow molding process, and the above-described hollow spaces between each other You can see what surrounds it. By means of the deformation tools 13 and 15, recesses 7 and 8 are formed at positions obvious from Fig. 2, that is, a recess 7 is formed by the first deformation tool 13, and the second A recess 8 is formed by the deformation tool 15.

As shown, the recess 7 has a closed end region 14, and the recess 8 has a second deformation tool 15 whose axial end is designed in a needle shape. ) By the opening. This opening is dimensioned so that the recess 7 with the closed end region 14 can at least partially enter.

The support structure 9 manufactured in this way prevents relative movement between the upper wall 5 and the lower wall 6, respectively, in the horizontal direction (in the intended use of the shoe with the shoe sole 1 described above). .

When the above-described hollow outsole body 4 is completed, the hollow space contained therein is filled with plastic bodies 10. This is shown in FIG. 3. To this end, the filling nozzle 19 is inserted into the opening 11 of the sole hollow body 4. Then, through the filling nozzle 19, spherical or elliptical plastic bodies 10 made of E-TPU (expanded thermoplastic polyurethane) are filled into the hollow outsole body 4 (in some cases, supported by pressurized air). May be), this continues until the sole hollow body 4 is completely filled with the plastic bodies 10. Regarding the material of the plastic bodies 10, hints for each publication have already been described above.

Essentially, the plastic bodies 5 are filled in the hollow space of the sole hollow body 4 as a loose material, so to speak, and are arranged in the hollow space without being connected to each other. Therefore, the plastic bodies 10 are not connected to each other. After filling of the sole hollow body 4, the plastic bodies 10 substantially support each other, but are arranged loosely relative to each other.

Accordingly, not only can the damping behavior of the sole (and hence the shoe) be very beneficially affected, but also the production process can be carried out easily and economically.

The filling process can be supported by evacuation of air, i.e. by application of a vacuum in the second opening 12 of the sole hollow body, and in some cases, after completion of this process, the air is transferred to the sole hollow body ( It can be discharged from the inside of 4) (refer to the arrow of the opening 12).

Each of the openings 11 and 12 may be closed after the filling process for the plastic bodies 10 is completed. Here, in particular the welding of these openings is taken into account. Accordingly, a hollow closed in a hermetically closed manner is created in the shoe sole 1 filled with the loosely disposed plastic bodies 10.

In cooperation with the support structure 9, it arbitrarily affects the spring and damping behavior of the shoe sole to a certain extent, but nevertheless gives the foot good stability with good stability of the sole in the intended use of the shoe provided with the shoe sole. The possibility is provided that what to keep will be provided.

In addition, Fig. 2 shows a preferred embodiment of the process described above. Here, a U-shaped insert 16 is shown which is inserted into its cavity prior to closing the blow mold 3. By the blow molding process, the insert 16 is firmly connected (welded) with the plastic hose 2 of the sole hollow body 4.

The insert 16 can be used to selectively influence the support function of the shoe sole 1. Preferably, the insert 16 is used as a heel shell to support the foot of a shoe user, wherein the shoe sole is provided in the rear region, ie the heel region.

1 shoe sole
2 plastic hose
3 blow mold
4 outsole hollow body
5 walls
6 walls
7 recess
8 recess
9 Support structure
10 plastic body
11 first opening
12 second opening
13 first transformation tool
14 closed end area
15 second transformation tool
16 insert
17 extrusion head
18 extruder
19 filling nozzle

Claims (15)

As a method of manufacturing a shoe sole (1),
a) A plastic hose (2) is extruded to supply the plastic hose (2) into the blow mold (3), or a plastic blank is injection molded to the plastic blank (3). Supplying;
b) blow molding the plastic hose (2) or the plastic blank into a sole hollow body (4), wherein the mutually opposed walls (5) of the sole hollow body (4) during the blow molding process , 6) by introducing recesses (7, 8), the portions of the walls (5, 6) come into contact with each other, the support structure between the mutually opposed walls (5, 6) ( 9) forming, the blow molding step;
c) removing the blow molded sole hollow body (4) from the blow mold (3);
d) filling the hollow part or the entire hollow of the blow-molded sole hollow body 4 with plastic bodies 10, wherein the plastic bodies 10 include the first opening of the hollow sole body 4 ( 11) is added through the filling step; including,
The dimensions of the single plastic bodies 10 in the three spatial directions are 1mm to 13mm, and the plastic bodies 10 are E-TPU (expanded thermoplastic polyurethane), E-TPE (expanded thermoplastic elastomere), and EPP (expanded polypropylene). ) Comprising any one or more of;
The production of the support structure 9 is achieved by means of a first deformation tool 13 in the recess, with a closed end region 14 in one of the walls 5. Create a recess 7 on one of them and also create a recess 8 on the other side with an open end region in the wall 6 on the other by means of a second deformation tool 15 And the closed end region 14 of one of the recesses 7 is designed to fit within the open end of the other recess 8 . The method of claim 1,
Shoe sole manufacturing method, characterized in that a sphere, ellipsoid or cylindrical body is used as the plastic bodies (10). The method of claim 2,
A shoe sole manufacturing method, characterized in that the dimensions of the single plastic bodies (10) in three spatial directions are 3mm to 6mm. The method of claim 1,
The plastic body 10 is a shoe sole manufacturing method, characterized in that composed of a foamed plastic material. The method of claim 1,
The plastic body 10 is a shoe sole manufacturing method, characterized in that consisting of E-TPO (expanded thermoplastic elastomere based on olefin). The method of claim 1,
The sole hollow body (4) is a shoe sole manufacturing method, characterized in that consisting of any one or more of TPU (thermoplastic polyurethane), TPE (thermoplastic elastomere), PA (polyamide) and rubber material. The method of claim 1,
A method for manufacturing a shoe sole, characterized in that after step d) according to claim 1, the first opening (11) is sealed. The method of claim 1,
A method of manufacturing a shoe sole, characterized in that during or after step d) according to claim 1, air is discharged from the hollow sole (4). The method of claim 1,
The plastic body (10) is a shoe sole manufacturing method, characterized in that arranged in the hollow body (4) without being connected to each other. The method of claim 1,
The plastic body (10) is a shoe sole manufacturing method, characterized in that arranged under pressure in a full package (full package) in the hollow outsole body (4). delete The method of claim 1,
Before the blow mold (3) is closed and step b) according to claim 1 is carried out, an insert (16) is placed in the blow mold (3), so that the insert (16) is A method of manufacturing a shoe sole, characterized in that it is connected with the sole hollow body (4) during the molding process. The method of claim 12,
The insert 16 is a shoe sole manufacturing method, characterized in that pre-fabricated by an injection molding process. The method of claim 12,
The insert (16) is a shoe sole manufacturing method, characterized in that it has a U-shaped design. The method of claim 12,
The insert 16 is a shoe sole manufacturing method, characterized in that consisting of TPU (thermoplastic polyurethane).

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